Class Four Flashcards
what do kinetics tell us about spontaneity
nothing
what is a step intermediate
substance that is produced in one step and consumed in another
rate determining step
slowest step in a process that determines the overall reaction
rate of reaction
how fast reactants are being consumed or how fast products are being formed
3 things reaction rate is determined by
how frequently the reactant molecules collide
the orientation of the colliding molecules
their energy
what is the activation energy
minimum energy required of reactant molecules for the reaction to proceed to products
what is the activation energy
minimum energy required of reactant molecules for the reaction to proceed to products
energy maximum of a reaction coordinate diagram
transition state
the lower the AE, the ___ the reaction rate
faster
the greater the conc. of reactants, the ___ the reaction rate
faster
the higher the temp of reaction, the ____ the reaction rate
faster
what does a catalyst do
accelerates a reaction by lowering the AE
do catalysts affect equilibrium
no
rate law is usually given as..
the rate at which reactant disappears
what is included in the rate law expression
only stuff that is involved in the rate determining step (slow step)
first order rate law is seen in..
unimolecular elementary steps
second order rate law is seen in..
bimolecular elementary steps
when a reaction is at equilibrium..
the rate of the forward reaction is equal to the rate of the reverse reaction
if keq < 1
reaction favours reactants
if keq = 1
reaction has equal amounts of reactants and products
if keq > 1
reaction favours the products
if Q is less than keq
reaction will proceed in the forward direction
if Q is greater than keq
reaction will proceed in the reverse direction
if the volume is reduced (pressure increases) so..
reaction favours the side with the smaller number of moles
if the volume is increased (pressure decreases) so..
reaction favours the side with more moles
lowering temperature favours ____ reactions
exothermic
raising temperature favours _____ reactions
endothermic
what are electrolytes
free ions in solution (from when ionic substances dissolve)
example of nonelectrolytes
covalent compounds
what does the van’t Hoff factor tell us
how many ions one unit of substance will produce in a solution
van’t Hoff factor for most biomolecules
1
solubility of solids in liquids ___ with increasing temp
increases
solubility of gases in liquids ____ with increasing temp
decreases
solubility of gases in liquids _____ with increasing pressure
increases
what salts are soluble in water (5)
group 1 salts
ammonium salts
nitrate, perchlorate & acetate salts
what salts are insoluble in water (3)
silver, lead and mercury salts
if Qsp < Ksp
more salt can be dissolved
if Qsp = Ksp
solution is saturated
if Qsp > Ksp
excess salt will precipitate
what is a complex ion
complex ions consist of metallic ions surrounded by Lewis bases
thermodynamics and eq formula
delta Go = -RTlnkeq
if delta Go < 0 and keq > 1
products are favoured at equilibrium
if delta Go = 0 and keq = 1
products & reactants are present in equal amounts
if delta Go > 0 and keq < 1
reactants are favoured at equilibrium
what does k depend on
temperature
what does q depend on
concentration and temperature
